package com.mzhmxh.util;


import org.springframework.stereotype.Component;

import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.util.Random;

/**
 * @Author Chronos
 * @Date 2019/12/9 8:32 下午
 * @Version 1.0
 * @package com.colin.util
 **/
@Component
public class CodeUtil {
        public static final String RANDOM_CODE_KEY= "RANDOMVALIDATECODEKEY";
        private static String randString = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
        private static int width = 95;
        private static int height = 25;
        private static int lineSize = 40;
        private static int stringNum = 4;

        private static Random random = new Random();

        private static Font getFont() {
            return new Font("Fixedsys", Font.CENTER_BASELINE, 18);
        }

        private static Color getRandColor(int fc, int bc) {
            if (fc > 255) {
                fc = 255;
            }
            if (bc > 255) {
                bc = 255;
            }
            int r = fc + random.nextInt(bc - fc - 16);
            int g = fc + random.nextInt(bc - fc - 14);
            int b = fc + random.nextInt(bc - fc - 18);
            return new Color(r, g, b);
        }

        public static void getRandCode(HttpServletRequest request, HttpServletResponse response) {
            HttpSession session = request.getSession();
            BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_BGR);
            Graphics g = image.getGraphics();
            g.fillRect(0, 0, width, height);
            g.setFont(new Font("Times New Roman", Font.ROMAN_BASELINE, 18));
            g.setColor(getRandColor(110, 133));
            for (int i = 0; i <= lineSize; i++) {
                drawLine(g);
            }
            String randomString = "";
            for (int i = 1; i <= stringNum; i++) {
                randomString = drawString(g, randomString, i);
            }

            session.removeAttribute(RANDOM_CODE_KEY);
            session.setAttribute(RANDOM_CODE_KEY, randomString);
            g.dispose();
            try {
                ImageIO.write(image, "JPEG", response.getOutputStream());
            } catch (Exception e) {
                e.printStackTrace();
            }

        }

        private static String drawString(Graphics g, String randomString, int i) {
            g.setFont(getFont());
            g.setColor(new Color(random.nextInt(101), random.nextInt(111), random
                    .nextInt(121)));
            String rand = String.valueOf(getRandomString(random.nextInt(randString
                    .length())));
            randomString += rand;
            g.translate(random.nextInt(3), random.nextInt(3));
            g.drawString(rand, 13 * i, 16);
            return randomString;
        }

        private static void drawLine(Graphics g) {
            int x = random.nextInt(width);
            int y = random.nextInt(height);
            int xl = random.nextInt(13);
            int yl = random.nextInt(15);
            g.drawLine(x, y, x + xl, y + yl);
        }

        public static String getRandomString(int num) {
            return String.valueOf(randString.charAt(num));
        }

}
